This is a fairly big topic. I am not sure that you will get a definitive answer from enotes or from one source, in general. I would say that social and civil reform from the 1800s to the present can find resonance in the idea of expanding individual voice. In both civil and social realms, I see this as one of the most dominant themes to compare change from then to now. One of the largest elements in social or civil reform from the 19th century to today is the idea of including more voices in the political and social lexicon. We can go back to the first Feminists like Cady Stanton or Anthony, or go back to thinkers like Douglass, Du Bois, and Washington who were driven by the idea of how people of color would function in the new nation. The Muckrakers and Progressivist spirit was about this idea of accounting for those who were not accounted, giving power to the supposed powerless. I think that this becomes a very important idea in social reform from the 19th Century to the modern setting as it helped to establish the idea of how individuals are going to be represented in a growing social and political order that reflects heterogeneity and diversity.